1. Technical Field
The present disclosure relates to power supply circuits and methods, and particularly to a power supply circuit of an audio codec chip and a method for providing power supply to the audio codec chip.
2. Description of Related Art
In computer systems, an audio codec chip is generally arranged on a computer motherboard to provide sound function for the computer. The audio codec chip is connected to a power supply terminal on the motherboard, so as to provide a working voltage for the audio codec chip. When the power supply terminal outputs 3.3 volts (V) to the audio codec chip, the voltage is divided and a small portion goes to a digital/analog signal transforming circuit (DAC) of the audio codec chip. The DAC detects the signal state of the input voltage signal. If the signal input into the DAC is at low level, the audio codec chip will start normal. If the signal input to the DAC is at high level however, then the audio codec chip will malfunction. When the computer motherboard is used with some types of power supply, such as and FSB ATX3000-68PD power supply, the divided voltage provided to the transforming circuit will be 0.9V. For some types of audio codec chip, the 0.9V voltage will be considered high rather than low level and the audio codec chip will malfunction.